The following design was proposed in another thread. This diagram shows some improvements I thought of.

This diagram is the valve in the closed position. The red part is the slider, which could be a coupler or similar. The blue circles are O-rings. The barrel, which is coaxially mounted in the tee housing, is capped at the back. The light blue is compressed air. The green is a sear (I think it's called that) that keeps the slider from being pushed open. The left O-ring blocks air from the sear. The only part not in the diagram is O-rings that would be mounted either inside the slider or outside the barrel, where the hole is in the next diagram. This prevents air from leaking (duh )

This diagram shows the slider when open. The right O-ring is to prevent too much air from escaping through the hole for the sear. Some air will escape during opening, but it wouldn't be much. (Those of you with sweaty hands might find it handy!) The sear is pulled down, and the slider is pushed forward. A blocker would be necessary to prevent further sliding, which is not pictured. This design could work co-axially, but I decided to show it in a tee, so that the flow would be maximized. It would not matter where the fill point is, because there is no pilot. A spring could be used to return the slider to closed position.

Sorry for the lousy explanation/diagrams

The main advantage/improvement with this design is that it eliminates piloting altogether, and can be adapted to fit almost any configuration, such as co-axial or over-under.

I kind of wondered about surface area too, but I figured this design would be most useful for large bore cannons, as we already have QEV's for small ones. I estimate the exposed area would be roughly 1.5" on a 3" barrel version of this design, which, at 100 psi, should be plenty of area

A spring could be used to return the slider to closed position.

Don't blame you for missing it... it was kind of buried also, it could be reset manually if you drilled a hole in the side, kind of like a bolt action rifle (hard to describe how it would work here, I can see it in my head, but I can't illustrate it )

jrrdw

Well, that's kind of the problem... the title was something along the lines of "new valve type", but I couldn't find it. It was made at least a month ago, more like 2. I'll keep looking, but I can't make promises

@ pilgrimman - I did seem to miss that, but it could work, though you would need one that could overcome the friction that the o-rings cause, both on the outside and inside of the slider, yet at the same time, is weak enough to be overcome by the air pressure on the surface area of the slider. Basically you need to get all the math done to figure out hom much pressure you'd need out of it. Cause guess and check in that scenario would be a b****. (as mr.crowly said.

Aye, I think I know what your talking about as far as the bot goes...

That look about right?

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